Steam generator

ABSTRACT

For use in an electric home appliance, such as steam mop or steam vacuum cleaner, a steam generator is disclosed to include an electric heater, a fluid storage tank connected to the electric heater, a pressure valve installed in the fluid storage tank and an air compression unit operable by hand, electricity or steam to pump air into the fluid storage tank to force fluid out of the fluid storage tank to the electric heater for heating into steam for application.

BACKGROUND OF THE INVENTION

(a) Field of the Invention

The present invention relates to apparatus for generating steam and more particularly, to a steam generator practical for use in an electric home appliance, such as steam mop or steam vacuum cleaner.

(b) Description of the Prior Art

Some electric home appliances, such as steam mop, steam vacuum cleaner and steam iron, need to use steam. These electric home appliances commonly have a steam generator mounted therein for generating steam. A steam generator is know, as show in FIG. 1, comprising a heating core 10, a water tank 20 and a manual or electric water pump 30. The heating core 10 can be, for example, an electric heater tube that generates heat when electrically connected. The water tank 20 has a water pipe 201 connected to the heating core 10. The water pump 30 is installed in the bottom side of the water tank 20 or the water pipe 201 for pumping water out of the water tank 20. When used in an electric home appliance, the water pump 30 is operated manually or electrically to pump water out of the water tank 20 through the water pipe 201 into the heating core 10 where water is heated into steam for application. However, the operation of this steam generator is to pump the water out of the water tank 20 by the water pump 30.

SUMMARY OF THE INVENTION

The present invention has been accomplished to provide an innovative steam generator, which utilizes the known physical law to force a fluid out of a fluid storage tank into an electric heater for generating steam. It is the main object of the present invention to provide a steam generator, which is to have an electric heater, a fluid storage tank, a pressure valve and an air compression unit arranged together in such a manner that when an air pressure is given to the inside of the fluid storage tank by the air compression unit, a pressure is evenly distributed to the fluid in the fluid storage tank subject to Pascal's principle, forcing the fluid to flow into the inside of the electric heater where the fluid is heated into steam for application. Thus, the steam generator can deliver fluid from the fluid storage tank to the electric heater without using any water pump. Therefore, the steam generator is practical for home use and allows easy regulation of the amount of fluid and steam.

To achieve this and other objects of the present invention, a steam generator comprises an electric heater for heating a fluid into steam, which comprises an electric heating member, a fluid inlet for guiding in a fluid to the electric heating member for heating into steam by the electric heating member and a first steam outlet for guiding out generated steam, a fluid storage tank, which comprises a fluid chamber holding a fluid, a fluid supply pipe arranged at a bottom side thereof and connected to the fluid inlet of the electric heater for guiding the fluid out of the fluid chamber into the electric heater for heating by the electric heating member, a pressure valve, which is mounted on the outside of the fluid storage tank and kept in communication with the fluid chamber for discharge of excessive air pressure out of the fluid storage tank, and an air compression unit, which is connected to the air inlet of the fluid storage tank and adapted for pumping air into the fluid chamber of the fluid storage tank to force the fluid out of the fluid chamber into the electric heater for heating into steam by the electric heating member.

This, the steam generator enables the air compression unit to output air into the fluid storage tank, increasing the internal pressure of the fluid chamber of the fluid storage tank to force the fluid out of the fluid chamber into the electric heater for generating steam. Thus, the invention can deliver fluid without using any water pump. The steam generator of the invention is practical for home use, allowing easy regulation of the amount of fluid and steam.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic drawing illustrating a steam generator according to the prior art.

FIG. 2 is a schematic drawing illustrating a steam generator in accordance with a first embodiment of the present invention.

FIG. 3 illustrates the operation of the air compression unit of the steam generator in accordance with the first embodiment of the present invention (I).

FIG. 4 illustrates the operation of the air compression unit of the steam generator in accordance with the first embodiment of the present invention (II).

FIG. 5 is a schematic drawing illustrating a steam generator in accordance with a second embodiment of the present invention.

FIG. 6 is a schematic drawing illustrating a steam generator in accordance with a third embodiment of the present invention.

FIG. 7 illustrates the operation of the air compression of the steam generator in accordance with the third embodiment of the present invention (I).

FIG. 8 illustrates the operation of the air compression unit of the steam generator in accordance with the third embodiment of the present invention (II).

FIG. 9 illustrates the operation of the air compression unit of the steam generator in accordance with the third embodiment of the present invention (III).

FIG. 10 corresponds to FIG. 2, illustrating an air pressure regulating valve installed in the air intake pipe and a one-way valve installed in the fluid supply pipe.

FIG. 11 corresponds to FIG. 5, illustrating an air pressure regulating valve installed in the air intake pipe and a one-way valve installed in the fluid supply pipe.

FIG. 12 corresponds to FIG. 6, illustrating an air pressure regulating valve installed in the air intake pipe and a one-way valve installed in the fluid supply pipe.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to FIG. 2, a steam generator in accordance with a first embodiment of the present invention is shown comprising an electric heater 1, a fluid storage tank 2, a pressure valve 3 and an air compression unit 4.

The electric heater 1 comprises an outer shell 11, an electric heating member 12 mounted in the outer shell 11, a fluid inlet 13 connected to the outer shell 11 for guiding a fluid into the inside of the outer shell 11 for heating by the electric heating member 12 into steam, and a steam outlet 14 connected to the outer shell 11 for guiding generated steam out of the outer shell 11.

The fluid storage tank 2 is an enclosed container, having a fluid chamber 21 defined therein, a fluid supply pipe 22 extended from bottom side of the fluid chamber 21 and connected to the fluid inlet 13 of the electric heater 1 and an air inlet 23 located on the top side thereof in communication with the fluid chamber 21. A fluid 7 is stored in the fluid chamber 21 for providing to the electric heater 1 for generating the desired steam.

The pressure valve 3 is mounted on the outside of the fluid storage tank 2 in communication with the fluid chamber 21 for discharging excessive air pressure. The pressure valve 3 comprises a valve body 31, a stopper 32 and a spring member 33. The stopper 32 is supported on the spring member 33 inside the valve body 31 and movable in one specific direction for enabling the pressure valve 3 to discharge air.

The air compression unit 4 is adapted to force out air. The air compression unit 4 can be a hand pump connected to the air inlet 23 of the fluid storage tank 2.

The air compression unit 4 can be operated to pump air into the fluid chamber 21 of the fluid storage tank 2 to impart a pressure evenly to the fluid 7 in the fluid chamber 21 subject to Pascal's principle, forcing the fluid 7 to flow through the fluid supply pipe 22 and the fluid inlet 13 into the inside of the outer shell 11 of the electric heater 1 where the fluid 7 is heated by the electric heating member 12 into steam for output through the steam outlet 14.

Referring to FIGS. 3 and 4 and FIG. 2 again, the air compression unit 4 comprises a housing 41 and a piston rod 42. The housing 41 has an air outlet 411 located on its one end and connected to the air inlet 23 of the fluid storage tank 2, and a piston hole 412 located on its other end for the passing of the piston rod 42. The piston rod 42 has a piston 421 fixedly connected to its front end. The piston 421 fits the inside wall of the housing 41 and axially movable with the piston rod 42 relative to the housing 41 to pump air out of the housing 41 into the fluid chamber 21 of the fluid storage tank 2. The air outlet 411 of the housing 41 may be directly connected to the air inlet 23 of the fluid storage tank 2. Alternatively, as shown in FIG. 2, an air intake pipe 24 is connected between the air outlet 411 of the housing 41 and the air inlet 23 of the fluid storage tank 2. When the user reciprocates the piston rod 42, the piston 421 is moved back and forth in the housing 41 to pump air into the fluid chamber 21 of the fluid storage tank 2, forcing the fluid 7 to flow to the inside of the electric heater 1.

FIG. 5 illustrates a steam generator in accordance with a second embodiment of the present invention. This second embodiment is substantially similar to the aforesaid first embodiment with the exception the structure of the air compression unit. According to this second embodiment, the air compression unit, referenced by 4 a, is electrically operated, comprising an air pump 41 a and a drive 42 a (for example, motor) adapted to move the air pump 41 a in pumping air. The air pump 41 a comprises an air outlet 411 a connected to the air inlet 23 of the fluid storage tank 2. The air outlet 411 a of the air pump 41 a may be directly connected to the air inlet 23 of the fluid storage tank 2. Alternatively, an air intake pipe 24 is connected between the air outlet 411 a of the air pump 41 a and the air inlet 23 of the fluid storage tank 2. When the drive 42 a is started up, the air pump 41 a is moved to pump air into the fluid chamber 21 of the fluid storage tank 2, forcing the fluid 7 to flow to the inside of the electric heater 1.

FIGS. 6˜9 illustrate a steam generator in accordance with a third embodiment of the present invention. According to this third embodiment, the electric heater 1 further comprises a second steam outlet 15 located on the outer shell 11 and a steam pipe 16 extended from the second steam outlet 15 and connected to the air compression unit, referenced by 4 b. The air compression unit 4 b is connected to the air inlet 23 of the fluid storage tank 2. Thus, the steam generated by the electric heater 1 can drive the air compression unit 4 b to pump air into the fluid chamber 21 of the fluid storage tank 2. According to this third embodiment, the air compression unit, referenced by 4 b, comprises a housing 41 b and a piston rod 42 b. The housing 41 comprises a partition plate 411 b transversely arranged therein on the middle, a first chamber 412 b and a second chamber 413 b separated by the partition plate 411 b, a piston hole 414 b cut through the partition plate 411 b in communication between the first chamber 412 b and the second chamber 413 b, an air inlet 415 b located on one end of the housing 41 b in communication with the first chamber 412 b and connected to the steam pipe 16, an air outlet 416 b located on the other end of the housing 41 b in communication with the second chamber 413 b and connected to the air inlet 23 of the fluid storage tank 2. The piston rod 42 b is inserted through the piston hole 414 b, having a piston 421 b fixedly connected to each of the two distal ends thereof. The two pistons 421 b are respectively movably accommodated in the first chamber 412 b and the second chamber 413 b.

Thus, as shown in FIG. 6, the steam generated by the electric heater 1 flows out of the first steam outlet 14 and the second steam outlet 15. The steam coming out of the second steam outlet 15 flows through the steam pipe 16 into the first chamber 412 b to move the respective piston 421 b in the first chamber 412 b, forcing the piston rod 42 b toward the second chamber 413 b, and at the same time the piston 421 b in the second chamber 413 b pumps air out of the housing 42 through the air outlet 416 b into the air inlet 23 of the fluid storage tank 2 to force the fluid 7 toward the electric heater 1. This operation cycle is repeated again and again to supply the cold fluid 7 to the electric heater 1 automatically and continuously.

Referring to FIGS. 10˜12, for allowing adjustment of the flow rate and speed of the supply of air from the air compression unit 4;4 a;4 b to the air inlet 23 of the fluid storage tank 2 to further control the internal pressure of the fluid chamber 21, an air pressure regulating valve 5 may be used and installed in the air intake pipe 24. The air pressure regulating valve 5 comprises a movable valve block 51. Moving the valve block 51 in the air pressure regulating valve 5 relatively regulates the flow rate and speed of the supply of air from the air compression unit 4;4 a;4 b to the air inlet 23 of the fluid storage tank 2 to further control the internal pressure of the fluid chamber 21, and therefore the flow rate and speed of the fluid 7 flowing from the fluid chamber 21 to the electric heater 1 is relatively controlled. Therefore the air pressure regulating valve 5 can control the amount and temperature of steam generated by the electric heater 1.

Referring to FIGS. 2, 5 and 6 again, a one-way valve 6 is installed in the fluid supply pipe 22 of the fluid storage tank 2 for allowing flowing of the fluid 7 from the fluid chamber 21 to the electric heater 1 and prohibiting reverse flow of the fluid 7 from the electric heater 1 back to the fluid chamber 21. The one-way valve 6 can be made in any of a variety of commercially available forms. Thus, when the air compression unit 4;4 a;4 b is stopped, the fluid 7 will not flow backwardly from the electric heater 1 to the fluid chamber 21. The functioning of the one-way valve 6 can also prohibit flowing of the generated steam from the electric heater 1 to the fluid chamber 21, assuring flowing of the generated steam out of the outer shell 11 through the first steam outlet 14 and the second steam outlet 15.

The design of the steam generator in accordance with the present invention enables the air compression unit 4;4 a;4 b to output air into the fluid storage tank 2, increasing the internal pressure of the fluid chamber 21 of the fluid storage tank 2 to force the fluid 7 out of the fluid chamber 21 into the electric heater 1 for generating steam. Thus, the invention can deliver fluid without using any water pump. The steam generator of the invention is practical for home use, allowing easy regulation of the amount of fluid and steam.

Although particular embodiments of the invention have been described in detail for purposes of illustration, various modifications and enhancements may be made without departing from the spirit and scope of the invention. Accordingly, the invention is not to be limited except as by the appended claims. 

What is claimed is:
 1. A steam generator, comprising: an electric heater for heating a fluid into steam, said electric heater comprising an electric heating member, a fluid inlet for guiding in a fluid to said electric heating member for heating into steam by said electric heating member and a first steam outlet for guiding out generated steam; a fluid storage tank, said fluid storage tank comprising a fluid chamber holding a fluid, a fluid supply pipe arranged at a bottom side thereof and connected to said fluid inlet of said electric heater for guiding said fluid out of said fluid chamber into said electric heater for heating by said electric heating member; a pressure valve mounted on the outside of said fluid storage tank and kept in communication with said fluid chamber for discharge of excessive air pressure out of said fluid storage tank; and an air compression unit connected to the air inlet of said fluid storage tank and adapted for pumping air into said fluid chamber of said fluid storage tank to force said fluid out of said fluid chamber into said electric heater for heating into steam by said electric heating member.
 2. The steam generator as claimed in claim 1, wherein said air compression unit is a hand pump operable to pump air into said fluid chamber of said fluid storage tank.
 3. The steam generator as claimed in claim 2, wherein said hand pump comprises a housing, said housing having an air outlet located on one end thereof and connected to the air inlet of said fluid storage tank and a piston hole located on and opposite end thereof, a piston rod inserted through said piston hole in an airtight manner, and a piston fixedly connected to one end of said piston rod and axially movable with said piston rod in said housing to force air out of said housing through the air outlet of said hand pump into the air inlet and fluid chamber of said fluid storage tank.
 4. The steam generator as claimed in claim 3, wherein said fluid storage tank further comprises an air intake pipe extended from the air inlet thereof and connected to the air outlet of said housing of said hand pump.
 5. The steam generator as claimed in claim 4, further comprising an air pressure regulating valve installed in said air intake pipe for regulating the flow rate of air passing out of said air compression unit into said fluid chamber.
 6. The steam generator as claimed in claim 1, wherein said air compression unit is electrically operated.
 7. The steam generator as claimed in claim 6, wherein said air compression unit comprises an air pump and a drive adapted for driving said air pump, said air pump having an air outlet connected to the air inlet of said fluid storage tank.
 8. The steam generator as claimed in claim 7, wherein said fluid storage tank further comprises an air intake pipe extended from the air inlet thereof and connected to the air outlet of said hand pump.
 9. The steam generator as claimed in claim 8, further comprising an air pressure regulating valve installed in said air intake pipe for regulating the flow rate of air passing out of said air compression unit into said fluid chamber.
 10. The steam generator as claimed in claim 1, wherein said electric heater further comprises a second steam outlet, a steam pipe extended from said second steam outlet and connected to said air compression unit for forcing said air compression unit to pump air into the air inlet of said fluid storage tank.
 11. The steam generator as claimed in claim 10, wherein said air compression unit comprises a housing, said housing comprising a partition plate transversely arranged therein on the middle, a first chamber and a second chamber defined therein and separated by said partition plate, a piston hole cut through said partition plate in communication between said first chamber and said second chamber, an air inlet located on one end of said housing in communication with said first chamber and connected to said steam pipe, and an air outlet located on an opposite end of said housing in communication with said second chamber and connected to the air inlet of said fluid storage tank, a piston rod inserted through said piston hole, and two pistons respectively fixedly connected to two distal ends of said piston rod and respectively movably accommodated in said first chamber and said second chamber for enabling said air compression unit to be driven said the steam passing out of said electric heater through said second steam outlet and said steam pipe to pump air into said fluid chamber of said fluid storage tank. 